Gas-operated automatic shotgun choke



Jan. 20, 1959 E. F. COYLE GAS-OPERATED AUTOMATIC SHOTGUN CHOKE Filed July 18, 1956 2,35%???2 Fatented .Fan. 2%, 1&59

GAS-OPERATED AUTOMATIQ SHOTGUN @HOKE Eugene F. Coyle, Hartford, 5. Dak.

Application July 18, 1956, Serial No. 598,674

4 Claims. (Cl. 42-79) The present invention appertains to improvements in devices for controlling the pattern and power of a charge from a shotgun and particularly relates to an improved and 'novel choke for shotguns.

'A primary object of the present invention is to provide a gun choke which, in attachment to the muzzle of a shotgun barrel, can be easily adjusted manually by means mounted on the forepiece of the shotgun so as to selectively provide a choked and an unchoked muzzle.

Another primary object of this invention is to provide ashotgun choke which is constructed to effect a choking action on a shot, as it is fired, rather than on a subsequent shot, so that the shot fired can be choked before it leaves the muzzle of the gun, such choking action being responsive to the firing of the shot itself.

Another important object of the present invention is to'pi'ovide a shotgun choke which can be easily adjusted manually to utilize the force of the gases of combustion to effect a choking action upon a charge as it is fired so that the muzzle will be constricted to concentrate the shot pattern of the shell which is fired.

A further important object of the present invention is to provide a shotgun choke which can be easily and simply attached to the muzzle of a shotgun, which can be'used to effect a quick choking of the gun in rapid firing and which is simply constructed and operated.

'A further important object of the'present invention is to provide a shotgun choke having a gas-actuated piston for choking the gun and a resilient means for returning the piston to a non-choking position, the piston being operated by gases of combustion of the charge and means being provided for selectively admitting the gases into a gas chamber behind the piston upon manual actuation of a control member mounted on the forepiece of the gun.

Other and further objects and advantages of the invention will be understood from the following detailed description thereof.

In the drawing:

Figure l is a longitudinal section through the improved choke with the choke mounted on the end of a shotgun barrel.

Figure 2 is a top plan view of the instant device, with parts broken away and parts depicted in section.

Figure 3 is a view taken substantially along lines 33 of Figure 1, and showing the gas ports in the operative position.

Figure 4 is a view similar to Figure 3, but showing the gas ports in a closed inoperative position.

Figure 5 is a side elevational view of a shotgun with the instant device attached in working position thereon.

As heretofore practiced in the manufacture of shotgun chokes, chokes have been gas-operated or operated by the exploding gas of the shotgun shell, in such a manner that the first shot fired operates the choke for the following shot, thus, the second shot is choked with respect to the first shot, since in some cases the initial shot fired from the shotgun is oftentimes a disabling or crippling shot, and the second or choked shot is a killing shot.

Should the operator desire not to have the second shot choked he must then manually manipulate the choke at the front portion of the barrel of the gun so as to not affect the second shot fired.

The instant invention provides a gas-operated shotgun choke having an operating handle or linkage which may be mounted on the forepiece of the shotgun so that during the use of the gun the operator may more readily control his shot pattern without undue manipulation of the gun to position the choke on the end of the barrel, thus providing for a more efficient operation of the gun at desired times.

Also, the instant invention provides a gas-operated choke which acts on the shot fired rather than on a subsequent shot. While one embodiment of the invention is illustrated in the above-referred-to drawing, it is to be understood that it is merely for the purpose of illustration and that various changes in construction may be resorted to in the course of manufacture in order that the invention may be utilized to the best advantage according to circumstances which may arise, without in any manner departing from the spirit and intention of the device, which is to be limited only in accordance with the appended claims. And while there is stated the primary fieldof utility of the invention, it remains obvious that it may be employed in other capacity wherein it may be found applicable.

Referring now more particularly to the accompanying drawing, the numeral 1d designates a conventional shotgun, shown in Figure 5, which includes a barrel 12 and a forepiece 14.

The choke 16 of the present invention is adapted to be attached to the muzzle end or outer end of the barrel 12 and is controlled by means positioned on the forepiece. The outer end of the barrel is externally threaded, as at 18, and the choke 16 comprises a sleeve 2-9 which has a coaxially enlarged internally threaded collar 22 at one end that is threaded on the outer end of the barrel so that the sleeve is attached tothemuzzle end of the gun barrel in axial alignment therewith. The sleeve 20 is formed with axially extending and circumferentially spaced slots 24 that pass radially through the sleeve providing fingers.

An annuiar jacket or cylindrical casing 26 is circumposed on the sleeve 2% and on' the muzzle end of the barrel, the jacket having inwardly extending annular end flanges 255 and 33". The flange 28 is a rearward flange and is provided with a collar 32 which is fixedly circumposed on the barrel by a set screw 34. The forward or frontflange 36 is provided with a small collar 36 which seats on an annular shoulder 38 on the outer end of the sleeve 2th The muzzle end of the barrel is provided with an annular ring of circumferentially spaced, radial gas ports 40 and a valve ring is rotatably circumposed on the muzzle end around the ports 40. The valve ring 42 is provided with radial outlet apertures 44 which are adapted to register with the ports 4th to permit the gases to escape to the rear portion 46 of the jacket, such portion 46 form ing a gas chamber.

A piston ring 43 is slidably fitted on the barrel and is connected by longitudinal rigidconnecting rods 50 with a forwardly spaced choke ring 52, the latter being adapted to close off the slots 24. A recoil spring 54 is seated at one end against the flange 3-6 and bears at its other end against the choke ring 52 to return the choke ring and the piston ring 48 to their normal positions, shown in Figure 1.

Means is provided for selectively registering the ports 4i) and the apertures 44 so as to permit the gases to enter the gas chamber 46, such means including an operating rod 56 which extends rearwardly and outwardly from the chamber 46 through the fiange 28 and is mounted on the forepiece 14 of the shotgun. A tab or finger piece 58 is provided on the rod 56, at the forepiece, for operating the rod. The front end of the rod 56 has'a link 69 secured universally thereto by a ball and socket 62. The link is fixed by a similar connection 64 to a radial offset on the valve ring 42 so that as the tab is rotated, the rod rotates to revolve the valve ring.

Operation Should the operator of the shotgun desire to have or leave his shotgun to fire a normal pattern, and does not desire the choke to operate, the tab 58 is positioned as shown in Figure 4 of the drawing. In such position, the valve ring 42 closes off the ports 40 and the choke will not operate.

Should the operator desire to choke the shotgun pattern, the same is done by placing the tab in the position shown in Figure 3, whereby the gas ports 40 and the apertures 44 are in alignment, allowing the gas to escape into the gas chamber 46, thereby pushing forward on the piston ring 43 and causing a resultant forward action on the choke ring 52, thereby closing the slots 24 of the choke sleeve 20, and the gun barrel is then in its choked position, to be returned to the position shown in Figure 1 after the shot has been fired, by means of the recoil spring 54.

Since the choke is adapted to operate on the shot fired rather than the next-succeeding shot, the firing or dis charging of the gas causes a very rapid choking of the gun, so that as the shot and wadding pass the gas ports 4-0, the gas is immediately allowed into the gas chamber 46, rapidly enough so that by the time the shot gets to the choke sleeve 20, it is choked already, and the choked pattern of the shot can thereby be accomplished.

The choking action will be maintained until the operator again places the tab 58 in the position shown in Figure 4 of the drawing thereby closing or sealing the gas ports 40.

From the foregoing specification, it will become apparent that the invention disclosed will adequately accomplish the functions for which it has been designed and in an economical manner, and that its simplicity, accuracy, and ease of operation are such as to provide a relatively inexpensive device, considering what it will accomplish, and that it will find an important place in the art to which it appertains when once placed on the market.

It is thought that persons skilled in the art to which the invention relates will able to obtain a clear understanding of the invention after considering the description in connection with the drawings. Therefore a more lengthy description is regarded as unnecessary.

Changes in shape, size and rearrangement of details and parts such as come within the purview of the invention claimed may be resorted to in actual practice, if desired.

What is claimed is:

l. A choke comprising a gun barrel with an externally threaded forward end and having circumferentially spaced radially disposed openings extended therethrough and spaced rearwardly from the forward end, a collar threaded on the forward end of the gun barrel, said collar having a sleeve with a tapering outer surface extended forwardly therefrom, the sleeve having radially disposed slots extended therethrough providing fingers and the diameter of the sleeve gradually enlarging from the collar to the forward end, a cylindrical casing surrounding the collar and sleeve and extended from a point spaced rearwardly from the radially disposed openings through the gun barrel to a plane corresponding with the extended ends of the fingers, the rearward end of the casing having an annular web therein and the web extending from the casing to the outer surface of the gun barrel providing a closure, a piston ring in the casing, slidably mounted on the gun barrel, and positioned forwardly of the radially disposed openings through the gun barrel, said web having a collar extended rearwardly therefrom and said collar being secured to the gun barrel for mounting the casing on the, gun barrel, and means actuated by the piston ring for contracting the fingers of the sleeve, the piston ring being driven forwardly by pressure of gases of combustion passing through the radially disposed openings of the gun barrel.

2. In combination with a choke as described in claim 1, means for adjusting the areas of the radially disposed openings through the gun barrel.

3. A choke as described in claim 1, in which the finger contracting means includes a choke ring also posi tioned in the casing and extended around the fingers, means connecting the choke ring to the piston ring whereby the gases of combustion passing through the radially disposed openings in the gun barrel drive both the piston ring and choke ring forwardly contracting the fingers and reducing the choke, and resilient means urging the piston and choke rings rearwardly of the casing.

4. A choke as described in claim 1, in which the finger contracting means comprises a choke ring positioned in the casing and extended around saidfingers, a spring positioned between the choke' ring and forward end of the casing, the forward end of the casing having an inwardly extended flange against which the spring is seated, rods connecting the choke and piston rings, a

. valve ring having openings therethrough positioned in the casing, and means for actuating the valve ring to regulate the areas of the radially disposed openings through the gun barrel.

References Cited in the file of this patent UNITED STATES PATENTS 2,779,119 Fawcett Jan. 29, 1957 

